ANF-TC is an additional network feature which limits the number of network
exchanges that a call request may transit during call establishment, e.g.
to protect the network against indefinite looping. There is no user involved
in the provision or operation of ANF-TC.

Additional network feature specifications are produced in three stages,
according to the method described in ETS 300 387. This Standard contains the stage 1 and stage 2 specifications of ANF-TC. The stage 1 specification (clause 6) specifies the general feature
principles and capabilities. The stage 2 specification (clause 7) identifies
the functional entities involved in the feature and the information flows
between them.